Radiator for electron discharge device



Original Filed June 29 1951 INVENTOR ATTORNElY v, E M m .f H

.- pssun xq RADIATOR FOR ELECTRON DISCHARGE iDEVICE 5""1 HM'PtQuLDail y, decea e .la of. ve n-1a, 1S Ja by T'Rut'h 1M. Dailey, m-sums, .yer a; 'N. 1., assignor fto Westinghouse El e tric Corporation, East Pittsburgh, '-=-Pa.,a*corporafion 6r{Pe i'isylv-iuiia Original application .iuiiel zia; 195,1, seri l are. 23.4315.

Divided and this spent-seen septemaer' 2s, mssrseual to radiators and more particularly, to radiators for electron discharge devices.

Present day transmitting tubes included in the general classification of electron discharge devices, are the source of intense heat during operation, and require radiators of good thermal conductivity and adequate surface area to disperse the generated heat. Radiators employing copper fins have been commonly used. While the tubes alone are relatively light, not usually exceeding twentyfive pounds, the copper radiators may be several hundred pounds, and thus require a crew of several men or a crane site for a successful radiator is that it must have a secure bond with the copper anode of the transmitting tube, but aluminum, for example, when fabricated, quickly forms a very stable oxide surface to which it is, for all practical purposes, impossible to make a good solder joint. This lack of adequate bond with the anode has prevented adoption of aluminum radiators for transmitting tubes, and similarly has prevented adoption of radiators of other light-weight metals and alloys.

Accordingly, the fundamental purpose of the present invention, is to provide a practical radiator of lightweight material, such as aluminum, for an electron discharge device and particularly for a transmitting tube in that classification.

Also, in general terms, an object of the invention is to provide an improved radiator of light-weight material such-as aluminum adaptable to attachment to a copper anode of an electron discharge device with a secure bond therewith.

More specifically, an object of the invention is to include within the radiator a means by which secure attachment between radiator and anode may be obtained.

Another object of the invention is to provide a. liner for the radiator which can be soldered to the anode.

Yet another object of the invention is to obtain a complete bond between the liner and the radiator hub or body.

A further object of the invention is to provide an improved method of fabrication.

Still other objects of the invention will appear to those skilled in the art to which it appertains as the description proceeds, both by direct recitation thereof and by implication from the context.

Referring to the accompanying drawings, in which like If it were possible to merely substitute3 1 2 4.2115. fi1 une,29,.195 1..now aband snat he 2,772,861 Patented Dec. 4,1956

numerals .of reference indicate similar parts throughout the several viewsz 7 Y 'Fig. 1 -a longi'tudinal sectionof a radiator fabricated in accordance with th'ezpresent invention and shown app'lied'toa'n anou g wmm depicted partly in section ahdpartl-y in elevation; r r

Fig. 2 is 'a transverse section ,on line llll ofFig. 1;

Fig. "3 is -a'mid-sectional view of the'centra'l hub of the radiator shown in Figs. 1 and- 2at one step i'n the course tifits-fabrication; if i :In the s'pecific embodime'nt of the invention illustrated in said drawingg theirefeiehce numeral 10 'd'es'ignate s an electron discharge dVice in general, having usual or other electrodes of which the anode 11 shown herein is formed as part of the envelope with which it is'a'ppropriately sealed so as to be evacuated, the lower end of said anode being closed as by an integrally formed dome 12. The anode is usually made of copper and in the construction shown is an exterior part of the tube so as to be available for heat dissipation.

The radiator, designated in general by numeral 13, comprises a hollow body or hub 14 from which, in radial planes, project a' plurality of fins 15. The present invention contemplates use of light-weight metal, such as aluminum, magnesium or alloys thereof, as the material of which said hub 14 and fins 15 are fabricated. The exterior cylindrical surface of the hub is milled with a plurality of longitudinal grooves 16, one for each fin, and the inner edges of the fins. are applied in the grooves and brazed or otherwise securely attached throughout their engaging portions with the hub.

The interior of the radiator body or hub is provided wit-h means for enabling the body to be securely attached to the anode throughout the juxtaposed surfaces after telescoping the said body upon the anode. According to the present invention, a metallic liner 17 is made integral with the said hub and constitutes the inner surface of the radiator body. Said liner is integrated with the hub so as to transmit heat by conduction from the anode to the hub and fins, and is of copper like the anode. The lower end of the liner 17 is hollowed to substantially conform to the curvature of dome 12.

In carrying out the method of fabrication, the liner is submerged to a point just below its rim in a pot of molten aluminum' 21 or equivalent metal, kept in its fluid state by inclusion in an electrically heated pot 22. In view of the direct contact of the outer surface of the liner with the molten aluminum, an excellent bond will form at the outer surface of the liner 17 because copper is soluble in molten aluminum. The liner may be kept cooler than the surrounding aluminum by any appropriate means (for instance insertion inside it of a massive slug of cooled copper) whereupon a-shell of solidified aluminum will form, growing radially outward from the liner 17. When the desired wall-thickness of solidified aluminum has formed, the unit may be withdrawn from the molten bath; or alternatively the heat may be shut off from the molten aluminum when the liner 17 is first immersed in it, and the whole mass of the molten aluminum be allowed to solidify. solidification from the core radially outward insures against the formation of pores and blowholes in the casting.

When the unit thus formed has cooled, it is machined to the desired size, and suitable slots to engage the inner edges of the fins are milled on its exterior surface. The fins may then be brazed into position.

After cleaning, solder is then introduced into the hollow of the radiator and heat applied until the solder is liquefied, flux is added, and the anode is then pressed into the hollow of the radiator until solder extrudes at the .top of the radiator cavity and the partshave desired relation. The solder willharden and tenaciouslyadhere to the liner and to the anode and provides an excellent heat-conductive path from the anode to the radiator. The .solder performs the function of providing .a secure bond which will not deteriorate by oxidation.

-. By providing a structure enabling the radiatorto be fabricated fromhaluminum or equivalent metal, a relatively light-weight radiator is obtained, and as comparative weights, it may be pointed out thatwhere a prior 10 art, copper radiator weighed-225 pounds, an equivalent aluminum radiator in accordance with the present invention weighs only-98 pounds,,thereby-enabling one, man to makesa tube replacementin'service. .Since handling can be done by one man, the apparatus may be more compactly arranged, thus saving'space inthe transmitter station. Furthermore, providing, lighter weightradiators of the present invention reduces shipping ,costsconsiderably.

I 1 claim:

' 1." An electron discharge device comprising "acopper qdaa l m u d a r oun e Q11 sa ano e,

l and the hub inseparably' integrating the liner and hub 15 as a unit. r

References Cited in the file of this patent UNlTED STATES PATENTS 2,181,366 Edwards'et a1. Nov. 28, 1939 2,288,380 1 Wing June 30, 1942 

1. AN ELECTRON DISCHARGE DEVICE COMPRISING A COPPER ANODE, AN ALUMINUM RADIATOR MOUNTED ON SAID ANODE, A LINER OF COPPER INTERPOSED BETWEEN THE ANODE AND RADIATOR, WITH A FUSED COPPER-ALUMINUM BOND INTEGRATING SAID LINER AND RADIATOR AS A UNIT, AND SOLDER INTERPOSED BETWEEN SAID ANODE AND LINER SECURING THE SAID LINER ON THE ANODE. 